Electro-optical device, method for fabricating the same, and electronic apparatus

ABSTRACT

An electro-optical device includes a pair of substrates including a first substrate and a second substrate, an electro-optical material sandwiched between the pair of substrates, a shading film having a predetermined pattern which is at least partially embedded in the first substrate at the surface facing the electro-optical material, display electrodes which are placed on the second substrate at the surface facing the electro-optical material, and lines connected to the display electrodes directly or through switching elements. In accordance with the electro-optical device having such a shading film, it is possible to reduce or prevent coating defects in an alignment layer, nonuniform rubbing treatment to the alignment layer, and cracking of a counter electrode due to the steps in the upper layers resulting from the formation of the shading film.

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] The present invention relates to an electro-optical deviceincluding a pair of substrates which sandwich an electro-opticalmaterial, such as liquid crystal. More particularly, the inventionrelates to an electro-optical device in which a shading film is providedon one of the substrates, such as a counter substrate, and the shadingfilm delimits the aperture regions for the individual pixels.

[0003] 2. Description of Related Art

[0004] Electro-optical devices, such as liquid crystal devices, exist inthe related art. One type of such a device is an active matrix liquidcrystal device in which thin-film transistors (hereinafter “TFTs”) forswitching pixels are provided. In such a liquid crystal device, pixelelectrodes are formed on a TFT array substrate provided with the TFTs,and a counter electrode is formed on a counter substrate which faces theTFT array substrate. While a plurality of pixel electrodes are arrayedin a matrix on the TFT array substrate, the counter electrode is formeduniformly over the entire surface of the counter substrate.Additionally, the TFTs are provided so as to correspond to theindividual pixel electrodes. Alignment layers are generally provided onthe pixel electrodes and the counter electrode, and a liquid crystal isinterposed between the upper and lower alignment layers.

[0005] In such an electro-optical device, a shading film, which isreferred to as a black matrix (BM) or black mask, formed of metallicchromium (Cr) or the like, is formed in a predetermined pattern, such asin a grid pattern or in a striped pattern, on the surface of the countersubstrate on which the counter electrode is to be formed, namely,between the counter electrode and the counter substrate, so as todelimit the aperture regions of the individual pixels (i.e., the regionsfrom which light actually contributing to display is emitted due totransmission or reflection), in other words, so as to delimit thenon-aperture regions of the individual pixels (i.e., the regions, otherthan the aperture regions, from which light actually contributing todisplay is not emitted due to transmission or reflection). The shadingfilm reduces or prevents light from leaking through the spaces betweenthe pixels. As a result, the image contrast can be enhanced, and when acolor filter is provided, color mixing can be reduced or prevented.

[0006] Additionally, the related art includes a technique for formingsuch a shading film, which delimits the aperture regions of theindividual pixels, partially or entirely on the TFT array substrate as aso-called embedded shading film. The related art also includes atechnique for constructing a shading film partially from the data lines,etc., on the TFT array substrate.

SUMMARY OF THE INVENTION

[0007] However, when a shading film pattern is formed on a countersubstrate as described above and a counter electrode and an alignmentlayer are formed thereon, since the shading film pattern has apredetermined height, steps occur in the counter electrode and thealignment layer corresponding to the sections at which the shading filmpattern is formed. Therefore, it is difficult to perform uniform rubbingtreatment on the alignment layer. There are also problems, such as theoccurrence of cracking in the counter electrode at the steps, andcoating defects in the alignment layer.

[0008] Moreover, recently, as electro-optical devices are miniaturized,the gap to form the liquid crystal layer tends to be decreased (forexample, to approximately 2 μm), and if the step height is excessive, itis not possible to secure a proper “thickness” for the liquid crystallayer. The presence of the steps is also problematic in this respect.

[0009] Additionally, recently, in order to fabricate an electro-opticaldevice having higher shading performance, a multilayered shading film,for example, in which a high reflectance layer is used for the lightincident side and a low reflectance layer is used for the reverse side,has been used in the related art. The height of the shading film patternhas inevitably increased, and the step height has also increased.Therefore, the problems described above have become serious. Forexample, the gap to form the liquid crystal layer is approximately 2 μmand the height of the shading film pattern is approximately 400 to 500nm.

[0010] The present invention addresses the problems described above, andprovides an electro-optical device in which a shading film having apredetermined pattern is incorporated in a substrate, such as a countersubstrate, and the undesirable effects of steps or irregularities due tothe presence of the shading film can be effectively reduced orprevented, and provides an electronic apparatus including theelectro-optical device.

[0011] A first electro-optical device of the present invention includesa pair of substrates including a first substrate and a second substrate,an electro-optical material sandwiched between the pair of substrates, ashading film having a predetermined pattern which is at least partiallyembedded in the first substrate at the surface facing theelectro-optical material, display electrodes which are placed on thesecond substrate at the surface facing the electro-optical material, andswitching elements provided at positions corresponding to the displayelectrodes.

[0012] In accordance with the first electro-optical device of thepresent invention, an electro-optical material, such as a liquidcrystal, is sandwiched between the first substrate, for example, acounter substrate, and the second substrate, for example, a TFT arraysubstrate. During operation, by supplying signals, such as imagesignals, from lines through the switching elements or directly to thedisplay electrodes formed on the second substrate, it is possible todrive the electro-optical material. The shading film having thepredetermined pattern can delimit, for example, the aperture regions ofthe individual pixels, and thus a high contrast ratio can be achievedand color mixing can be reduced or prevented.

[0013] Such a shading film is at least partially embedded in the firstsubstrate, for example, the counter substrate at the surface facing theelectro-optical material. Consequently, it is possible to reduce theheight of the steps or irregularities resulting from the presence of theshading film by an amount substantially the same as the embedding depth.Therefore, various undesirable effects of such steps or irregularitiescan be effectively reduced or prevented. Examples of the variousundesirable effects include the difficulty in performing rubbingtreatment uniformly on the alignment layer on the first substrate, theoccurrence of cracking in the counter electrode on the first substrate,and coating defects in the alignment layer on the first substrate.Moreover, it is possible to decrease the thickness of theelectro-optical material layer by about the same amount of the reductionof the steps or irregularities, and therefore it is possible to copewith the miniaturization of the electro-optical device.

[0014] As described above, in accordance with the first electro-opticaldevice of the present invention, while the shading film having thepredetermined pattern is incorporated in the first substrate, such as acounter substrate, the undesirable effects resulting from the presenceof the shading film can be effectively reduced or prevented.

[0015] Additionally, “the shading film . . . which is at least partiallyembedded” of the present invention means that at least a part of theshading film in the height direction is embedded. That is, when thesurface of the first substrate is considered as “the surface facing theelectro-optical material” of the present invention, “the shading filmwhich is at least partially embedded” means that the edges of theshading film slightly protrude from the substrate surface. Consequently,the shading film which is totally embedded means that the edges of theshading film are flush with the substrate surface. Either case isacceptable in the present invention.

[0016] The shading film . . . which is at least partially embedded” ofthe present invention also means that the shading film is at leastembedded in “the surface” of the present invention at least in someregions among the entire surface of the substrate. That is, in such acase, in the plane of the surface, the shading film is embedded in someregions, and the shading film is not embedded in the other regions.Consequently, the shading film which is totally embedded means that theshading film is totally embedded over the entire surface. Either case isacceptable in the present invention.

[0017] In an embodiment of the first electro-optical device of thepresent invention, a planarizing layer is formed flush with the surfaceof the shading film on the first substrate or at a higher level than theshading film.

[0018] In such a construction, since the shading film is at leastpartially embedded in the first substrate and also the planarizing layeris formed flush with the surface of the shading film or at a higherlevel than the shading film, it is possible to reduce the height of thesteps or irregularities resulting from the presence of the shading filmby an amount substantially the same as the embedding depth and by anamount substantially the same as the amount of planarizing.Consequently, various undesirable effects of such steps orirregularities can be effectively reduced or prevented. Moreover, it ispossible to decrease the thickness of the electro-optical material layerby an amount substantially the same as the reduction in the height ofthe steps or irregularities, and therefore it is possible to cope withthe miniaturization of the electro-optical device.

[0019] In another embodiment of the first electro-optical device of thepresent invention, an alignment layer is formed as an uppermost layer tothe shading film.

[0020] In such a construction, in the first substrate in which theshading film is at least partially embedded, which results in theprevention of the undesirable effects due to the steps orirregularities, since the alignment layer is formed as the uppermostlayer, coating defects do not occur when the alignment layer is formedby coating, and rubbing treatment can be performed uniformly on thesurface of the alignment layer after coating the alignment layer.

[0021] A second electro-optical device of the present invention includesa pair of substrates including a first substrate and a second substrate,an electro-optical material sandwiched between the pair of substrates, ashading film having a predetermined pattern which is formed on the firstsubstrate at the surface facing the electro-optical material, displayelectrodes which are placed on the second substrate at the surfacefacing the electro-optical material, switching elements provided atpositions corresponding to the display electrodes, and a planarizinglayer formed flush with the surface of the shading film on the firstsubstrate or at a higher level than the shading film.

[0022] In accordance with the second electro-optical device of thepresent invention, an electro-optical material, such as a liquidcrystal, is sandwiched between the first substrate, for example, acounter substrate, and the second substrate, for example, a TFT arraysubstrate. During the operation, by supplying signals, such as imagesignals, from lines through the switching elements or directly to thedisplay electrodes formed on the second substrate, it is possible todrive the electro-optical material. The shading film having thepredetermined pattern can delimit, for example, the aperture regions ofthe individual pixels, and thus a high contrast ratio can be achievedand color mixing can be reduced or prevented.

[0023] In particular, the planarizing layer is formed flush with thesurface of the shading film or at a higher level than the shading filmon the first substrate, for example, a counter substrate. Accordingly,it is possible to reduce the height of the steps or irregularitiesresulting from the presence of the shading film by an amountsubstantially the same as the amount of planarizing. Consequently,various undesirable effects of such steps or irregularities can beeffectively reduced or prevented. Moreover, it is possible to decreasethe thickness of the electro-optical material layer by an amountsubstantially the same as the amount of reduction in the steps orirregularities, and therefore it is possible to cope with theminiaturization of the electro-optical device.

[0024] As described above, in accordance with the second electro-opticaldevice of the present invention, while the shading film having thepredetermined pattern is incorporated in the first substrate, such as acounter substrate, undesirable effects resulting from the presence ofthe shading film can be effectively reduced or prevented.

[0025] In an embodiment of the electro-optical device of the presentinvention, the planarizing layer is formed by chemical mechanicalpolishing (CMP).

[0026] In such a construction, since the planarizing layer is obtainedby CMP, undesirable effects resulting from the steps or irregularitiescan be more reliably reduced or prevented. Herein, CMP is a technique inwhich the surfaces of a substrate and a polishing cloth (pad) arebrought into contact with each other while both the substrate and thepolishing cloth are rotated or the like, and simultaneously, a polishingliquid (slurry) is supplied to the contact section, and thus the surfaceof the substrate is planarized by polishing, taking advantages of thesynergistic effect of both mechanical and chemical actions.

[0027] In another embodiment of the present invention, the planarizinglayer is a spin-on-glass (SOG) film.

[0028] In such a construction, since the planarizing layer is composedof a SOG film, undesirable effects resulting from the steps orirregularities can be more reliably reduced or prevented. Herein, theSOG film is obtained by a technique in which an appropriate organicliquid or the like is applied to a substrate while rotating thesubstrate so that the liquid produces a horizontal surface, and then bysolidifying the liquid, a planarized surface is obtained.

[0029] In another embodiment of the present invention, theelectro-optical device further includes a color filter and an overcoatlayer formed on top of the color filter, the color filter and theovercoat layer being placed on the first substrate above or below theshading film, and the surface of the overcoat layer is planarized.

[0030] In such a construction, when the color filter, etc., is providedabove the shading film, the overcoat layer can be used as a planarizinglayer which planarizes the steps or irregularities produced by thepattern of the shading film. When the color filter, etc., is providedbelow the shading film, the shading film can be formed on the flatunderlayer composed of the overcoat layer.

[0031] In any case, in such a construction, it is possible to reduce orprevent undesirable effects resulting from the steps or irregularitiesin the electro-optical device provided with the color filter. In such aconstruction, it is also obvious that the shading film can reduce orprevent color mixing.

[0032] In another embodiment of the present invention, the shading filmis placed in a recess formed in the first substrate.

[0033] In such a construction, by placing the shading film in the recessformed in the first substrate, the shading film can be embedded in thesubstrate, and planarizing treatment can be performed on the layer abovethe shading film. Moreover, such a construction can be relatively easilyobtained by forming a recess having a predetermined pattern by etchingtreatment or the like in the first substrate.

[0034] Alternatively, in another embodiment of the present invention,the shading film is placed in a recess formed in an interlayerinsulating film formed on the first substrate.

[0035] In such a construction, by placing the shading film in the recessformed in the interlayer insulating film, the shading film can beembedded in the substrate, and planarizing treatment can be performed onthe layer above the shading film. Moreover, such a construction can berelatively easily obtained by forming a recess with a predeterminedpattern by etching treatment or the like in the interlayer insulatingfilm.

[0036] In another embodiment of the present invention, an overcoat layeris formed on top of the shading film.

[0037] In such a construction, since the overcoat layer formed on top ofthe shading film is the most appropriate layer on which planarizingtreatment is performed, planarization can be performed more reliably,and also undesirable effects resulting from the steps or irregularitiescan be reduced or prevented.

[0038] In another embodiment of the present invention, theelectro-optical device further includes an alignment layer as anoutermost layer on the first substrate.

[0039] In such a construction, the state of the electro-opticalmaterial, such as a liquid crystal, can be aligned by the alignmentlayer. Particularly, in the underlayer for the alignment layer, sincethe height of steps or irregularities is reduced because of embedding ofthe shading film or planarization treatment, the alignment layer can beformed satisfactorily by coating, and also rubbing treatment can beperformed uniformly on the alignment layer.

[0040] Additionally, the present invention is also applicable to anelectro-optical device in which the first substrate is not provided withan alignment layer.

[0041] In another embodiment of the present invention, theelectro-optical device further includes another display electrode whichis placed on the first substrate at the surface facing theelectro-optical material.

[0042] In such a construction, the electro-optical material, such as aliquid crystal, can be driven by a pair of display electrodes. In such acase, the combination of the pair of display electrodes may include apixel electrode and a solid counter electrode or a rectangular displayelectrode, or may include electrode strips which intersect each other.Particularly, in the underlayer for the display electrode on the firstsubstrate, since the height of steps or irregularities is reducedbecause of embedding of the shading film or planarization treatment,cracking can be reduced or prevented in the display electrode.

[0043] Additionally, the present invention is also applicable to anelectro-optical device in which the first substrate is not provided witha display electrode.

[0044] In this embodiment, the display electrode on the first substratemay be a transparent counter electrode formed over the entire imagedisplay region.

[0045] In such a construction, cracking in the transparent counterelectrode formed of an ITO film or the like can be effectively reducedor prevented.

[0046] In another embodiment of the present invention, theelectro-optical device further includes microlenses provided on thefirst substrate.

[0047] In such a construction, since light can be focused in thebeam-condensing regions on the display electrode, utilization of theincident light can be enhanced. In particular, in this embodiment, it ispossible to achieve such an effect while simultaneously eliminating theundesirable effects of steps or irregularities.

[0048] In another embodiment of the present invention, the shading filmincludes a plurality of layers.

[0049] In this embodiment, since the shading film includes a pluralityof layers, the shading performance of the shading film can be enhanced.For example, a high reflectance material may be used for the lightincident side and a low reflectance layer may be used for thelight-emitting side. When a multilayered shading film is formed, the“height” of the multilayered shading film is generally larger than thatof a single-layer shading film. However, in this embodiment, even if the“height” of the shading film is increased because of the multilayeredstructure, since the shading film is embedded in the first substrate orthe height of steps or irregularities is decreased by planarizationtreatment, a planarized surface can be obtained. The embodiment may bemore effective in the case in which such a shading film having a large“height” is used?

[0050] In this embodiment, if the plurality of layers are formed of analuminum layer, a chromium layer, and a chromium oxide layer, theshading performance can be further enhanced.

[0051] In order to address or overcome the problems described above, afirst method for fabricating an electro-optical device of the presentinvention includes: forming a shading film having a predeterminedpattern which is at least partially embedded in a first substrate at asurface to be facing an electro-optical material, forming displayelectrodes on a second substrate at a surface to be facing theelectro-optical material, forming switching elements corresponding tothe display electrodes, bonding the first substrate and the secondsubstrate with each other around the peripheries thereof, and injectingthe electro-optical material into the space between the bonded first andsecond substrates.

[0052] In accordance with the first method for fabricating theelectro-optical device, the first electro-optical device of the presentinvention described above (including the various embodiments thereof)can be fabricated relatively easily.

[0053] In order to address or overcome the problems described above, asecond method for fabricating an electro-optical device of the presentinvention includes: forming a shading film having a predeterminedpattern on a first substrate at a surface to be facing anelectro-optical material, performing planarization treatment on the sameplane as the surface of the shading film on the first substrate or onthe level above the shading film, forming display electrodes on a secondsubstrate at a surface to be facing the electro-optical material,forming switching elements corresponding to the display electrodes,bonding the first substrate and the second substrate with each otheraround the peripheries thereof, and injecting the electro-opticalmaterial into the space between the bonded first and second substrates.

[0054] In accordance with the second method for fabricating theelectro-optical device of the present invention, the secondelectro-optical device of the present invention described above(including the various embodiments thereof) can be fabricated relativelyeasily.

[0055] Finally, in accordance with electronic apparatuses of the presentinvention, since the electronic apparatuses include the electro-opticaldevices described above, it is possible to provide various types ofelectronic apparatuses which can display bright images with highcontrast and high resolution, such as liquid crystal televisions, mobilephones, electronic pocket diaries, word processors, viewfinder type ormonitor-direct-view type video tape recorders, workstations, televisiontelephones, POS terminals, and touch panels, for example.

[0056] The effects and other advantages of the present invention will beclarified by the embodiments which will be described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0057]FIG. 1 is a plan view of a TFT array substrate and elements formedthereon in an electro-optical device in an embodiment of the presentinvention, viewed from the counter substrate side;

[0058]FIG. 2 is a sectional view taken along plane H-H′ of FIG. 1;

[0059]FIG. 3 is an enlarged sectional view showing a circled sectionindicated by the symbol CR in FIG. 2;

[0060]FIG. 4 is an enlarged sectional view showing a similar section tothat in FIG. 3 in an embodiment in which a shading film is placed inrecesses formed in a counter substrate body;

[0061]FIG. 5 is an enlarged sectional view showing a similar section tothat in FIG. 4 in an embodiment in which a gap lies between a recess anda shading film;

[0062]FIG. 6 is an enlarged sectional view showing a similar section tothat in FIG. 4 in an embodiment in which a color filter and an overcoatlayer are provided above a shading film;

[0063]FIG. 7 is an enlarged sectional view showing a similar section tothat in FIG. 4 in an embodiment in which a color filter and an overcoatlayer are provided as underlayers to a shading film;

[0064]FIG. 8 is an enlarged sectional view showing a similar section tothat in FIG. 4 in an embodiment in which microlenses and a cover glassare provided as underlayers to a shading film;

[0065]FIG. 9 is a schematic showing a specific example of a shading filmwhich has a single-layer structure composed of only one material;

[0066]FIG. 10 is a schematic showing a specific example of a shadingfilm which has a two-layer structure composed of two materials;

[0067]FIG. 11 is a schematic showing a specific example of a shadingfilm which has a three-layer structure composed of three materials;

[0068]FIG. 12 is a schematic of a circuit diagram showing an equivalentcircuit including various elements, lines, etc., provided on a pluralityof pixels formed in a matrix which constitute the image display regionin an electro-optical device in an embodiment of the present invention;

[0069]FIG. 13 is a plan view showing a plurality of pixels placedadjacent to each other in a TFT array substrate provided with datalines, scanning lines, pixel electrodes, etc., in an electro-opticaldevice in an embodiment of the present invention;

[0070]FIG. 14 is a sectional view taken along plane A-A′ of FIG. 13;

[0071]FIG. 15 is a flowchart showing a fabrication process for a countersubstrate provided with elements in an electro-optical device in anembodiment of the present invention;

[0072] FIGS. 16(a) to 16(d) are schematics which illustrate the step offorming recesses in a counter substrate;

[0073] FIGS. 17(a) and 17(b) are schematics which illustrate the stepsof forming a shading film over the entire surface of a counter substrateprovided with recesses and performing CMP so that the shading filmremains only in the recesses and the surface is planarized;

[0074]FIG. 18 is a flowchart showing a fabrication process for a TFTarray substrate provided with elements in an electro-optical device inan embodiment of the present invention and a fabrication process for theentire electro-optical device; and

[0075]FIG. 19 is a sectional view which schematically shows a colorliquid crystal projector as an example of a projection color displaydevice in an embodiment of an electro-optical device of the presentinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0076] The embodiments of the present invention will be described belowwith reference to the drawings.

[0077] Overall Structure of Electro-Optical Device

[0078] First, the overall structure of an electro-optical device in afirst embodiment of the present invention will be described withreference to FIGS. 1 and 2. Herein, as an example of an electro-opticaldevice, a TFT active matrix liquid crystal device with built-in drivecircuits are described below.

[0079]FIG. 1 is a plan view of a TFT array substrate and elements formedthereon, viewed from the counter substrate side, and FIG. 2 is asectional view taken along plane H-H′ of FIG. 1.

[0080] As shown in FIGS. 1 and 2, in the electro-optical device in thefirst embodiment, a TFT array substrate 10, in which various elements,such as TFTs 30 and storage capacitors 70, which will be describedbelow, are provided on a TFT array substrate body, and a countersubstrate 20, in which various elements, such as a shading film 500 anda counter electrode 21, which will also be described below, are providedon a counter substrate body, are placed so as to face each other.

[0081] In this embodiment, “the first substrate” of the presentinvention corresponds to “the counter substrate body”.

[0082] A liquid crystal layer 50 is enclosed between the TFT arraysubstrate 10 and the counter substrate 20, and the TFT array substrate10 and the counter substrate 20 are bonded with each other by a sealant52 provided in the sealing region located in the periphery of an imagedisplay region 10 a. The sealant 52 is formed of, for example, athermosetting resin, a thermosetting and photo-curable resin, aphoto-curable resin, or UV curable resin, and after the resin is appliedonto the TFT array substrate 10 in the fabrication process, the resin ishardened by heating only, heating and irradiation, irradiation only, UVirradiation only, or the like.

[0083] A gap material, for example, glass fibers or glass beads, ismixed in the sealant 52 in order to maintain a predetermined gap betweenthe substrates. That is, the electro-optical device in this embodimentis suitable for use as a light valve for a compact projector whichproduces a magnified display. However, if the electro-optical device isused as a large liquid crystal device, such as a liquid crystal displayor a liquid crystal television, which produces a display with amagnification factor of 1, such a gap material may be contained in theliquid crystal layer 50.

[0084] As shown in FIGS. 1 and 2, a frame-shaped shading film 53 todetermine the periphery of the image display region 10 a is providedalong the inner sides of the sealing region on the counter substrate 20.However, a part or the entirety of such a frame-shaped shading film 53may be incorporated in the TFT array substrate 10.

[0085] A data line drive circuit 101, which drives data lines 6 a bysupplying image signals at a predetermined timing, and external circuitconnection terminals 102 are provided along one side of the TFT arraysubstrate 10 outside the sealant 52. Scanning line drive circuits 104,which drive scanning lines 3 a by supplying scanning signals at apredetermined timing, are provided along two sides adjacent to the sidedescribed above.

[0086] If delays in scanning signals supplied to the scanning lines 3 apresent no problem, the scanning line drive circuit 104 may be formed onone side only. Data line drive circuit 101 may be placed along bothsides of the image display region 10 a.

[0087] A plurality of lines 105 for connecting the scanning line drivecircuits 104 provided on both sides of the image display region 10 a areformed along the remaining side of the TFT array substrate 10. Aconductive member 106 is provided on at least one corner out of fourcorners of the counter substrate 20 to electrically connect the TFTarray substrate 10 and the counter substrate 20 with each other. Asshown in FIG. 2, the counter substrate 20, which has substantially thesame outline as that of the sealing region, is fixed to the TFT arraysubstrate 10 by the sealant 52.

[0088] In FIG. 2, on the TFT array substrate 10, an alignment layer isformed on pixel electrodes 9 a on which TFTs to switch pixels and lines,such as scanning lines and data lines, have been formed. On the otherhand, on the counter substrate 20, in addition to the counter electrode21, an alignment layer is formed as the outermost layer. The liquidcrystal layer 50 is formed of, for example, one nematic liquid crystalor a mixture of several types of nematic liquid crystals, and is in apredetermined alignment state between the pair of alignment layers.

[0089] Additionally, on the TFT array substrate 10 shown in FIGS. 1 and2, in addition to the data line drive circuit 101, the scanning linedrive circuits 104, etc., a sampling circuit which samples and suppliesimage signals to the data lines, a pre-charge circuit which suppliespre-charging signals at a predetermined voltage level to a plurality ofdata lines prior to image signals, an inspection circuit to inspect thequality and defects, etc., of the electro-optical device duringfabrication and at the time of shipment, and other circuits may beformed.

[0090] Instead of placing the data line drive circuit 101 and thescanning line drive circuits 104 on the TFT array substrate 10, they maybe electrically and mechanically connected, for example, to a drivingLSI mounted on a Tape Automated Bonding (TAB) substrate through ananisotropic conductive film provided in the periphery of the TFT arraysubstrate 10. Depending the operation mode, such as a Twisted Nematic(TN) mode, a Vertically Aligned (VA) mode, or a Polymer Dispersed LiquidCrystal (PDLC) mode, and a normally white or normally black mode,polarizing films, retardation films, polarizing plates, etc., are placedin the predetermined directions on the counter substrate 20 at the sidein which incident light enters and on the TFT array substrate 10 at theside from which light is emitted.

[0091] First Embodiment

[0092] Next, in an electro-optical device having the overall structuredescribed above, the structure and effect of the shading film providedon the counter substrate body will be described with reference to thedrawings.

[0093] The structure of a shading film 500 in a first embodiment will bedescribed with reference to FIGS. 2 and 3. FIG. 3 is an enlargedsectional view showing a circled section indicated by the symbol CR inFIG. 2.

[0094] The shading film 500 in the first embodiment is embedded in thecounter substrate 20 as shown in FIGS. 2 and 3. Herein, “embedded” meansthat, as shown in FIG. 3, after the shading film 500 is formed on thesurface of the counter substrate body 20R, an overcoat layer 600 isformed thereon. The overcoat layer 600 is formed of, for example, anacrylic resin or an epoxy resin. The thickness of the overcoat layer 600is, for example, approximately 0.5 to 2 μm.

[0095] The surface of the overcoat layer 600 is planarized by CMP or aSOG film formation process. Thereby, steps resulting from the formationof the shading film 500 do not appear on the surface of the overcoatlayer 600. In FIG. 3, a counter electrode 21 and an alignment layer 22are further formed on top of the overcoat layer 600. In the firstembodiment, the counter electrode 21 corresponds to “the other displayelectrode” of the present invention, and the pixel electrodes 9acorrespond to “the display electrodes” of the present invention.

[0096] The shading film 500 has a grid pattern when shown in a planview. The grid pattern corresponds to the pixel electrodes 9 a arrayedin a matrix on the TFT array substrate 10, and in the shading film 500,vertical and horizontal bands are placed orthogonal to each other so asto cover the spaces between the pixel electrodes 9 a. Consequently, theshading film 500 reduces or prevents light from leaking through thespaces between the pixels, thus enhancing the image contrast.

[0097] However, the present invention is not limited to the case inwhich the shading film 500 has the grid pattern as described above. Forexample, the shading film 500 may have a striped pattern or any othertype of patterns.

[0098] In this embodiment, in addition to the enhancement in thecontrast between the pixels, the shading film 500 also reduces orprevents light from entering the channel regions of the semiconductorlayers constituting the TFTs, thus reducing or preventing improperoperations and a decrease in image quality due to the generation ofphoto leakage current. In such a case, besides the shading film 500, thelower shading film, data lines, capacitor lines (all of which will bedescribed below), etc., also function as elements which display theshading function.

[0099] As described above, in the structure in which the shading film500 is embedded in the counter substrate 20, as shown in FIG. 3, theheight of steps or irregularities resulting from the formation of theshading film can be decreased considerably compared with the related artcase.

[0100] Consequently, cracking can be reduced or prevented in the counterelectrode 21, coating defects do not occur in the alignment layer, andrubbing treatment can be performed uniformly over the alignment layer.The decrease in the step height makes it possible to narrow thethickness of the liquid crystal layer 50, and as a result, theelectro-optical device can be miniaturized. That is, in theelectro-optical device in the first embodiment, undesirable effects ofthe steps or irregularities resulting from the formation of the shadingfilm can be effectively reduced or prevented.

[0101] Second Embodiment

[0102] A second embodiment of the present invention will be describedwith reference to FIG. 4. FIG. 4 is an enlarged sectional view similarto FIG. 3, but shows a different structure. In the second embodiment,the shading film 500 is embedded in the counter substrate 20 in such amanner in which recesses 700 are formed in the surface of the countersubstrate body 20R, and the shading film 500 is formed in the recesses700. In this embodiment, as will be also described with respect to thefabrication method, for example, the recesses 700 are formed in thecounter substrate body 20R in a predetermined pattern preliminarily, andthen a material for the shading film 500 is deposited in the recesses700 by sputtering or the like. In the second embodiment, in the samemanner as that in the first embodiment, the shading film 500 typicallyhas a grid pattern, and in such a case, the recesses 700 are also formedin a grid pattern. The counter substrate body 20R, which may also beapplied to other embodiments, is a transparent substrate, such as aglass substrate formed of quartz glass, neoceram, or the like, or aplastic substrate. The counter substrate body 20R may also be formed ofthe same material as or a different material from that for the TFT arraysubstrate 10.

[0103] As described above, in the electro-optical device in the secondembodiment, since the shading film 500 is embedded in the recessesformed in the surface of the counter substrate body 20R, a flattersurface can be obtained, and the effects in the first embodiment can bemore reliably produced.

[0104] In the second embodiment, it is also more effective to performthe planarization treatment, such as CMP or a SOG film formationprocess, described in the first embodiment before the formation of thecounter electrode 21, etc.

[0105] In the second embodiment, the shading film 500 is entirelyembedded in the counter substrate body 20R. However, the presentinvention is not limited to such a structure. That is, the shading film500 may be partially embedded in the counter substrate body 20R. In sucha structure, the undesirable effects of the steps can be reduced orprevented at least partially, and a considerable effect can be produced.

[0106] In the second embodiment, although FIG. 4 shows a structure inwhich the shading film 500 is embedded in the recesses 700 without agap, the present invention is not limited to such a structure. Forexample, as shown in FIG. 5, a gap G may be present between the shadingfilm 500 and a recess 701. Such a structure may be produced when thecoverage for the recess 701 is insufficient when the shading film 500 isformed. Conversely, the structure shown in FIG. 4 in the secondembodiment can be obtained by a special fabrication process, such as adamascene process.

[0107] In the structure shown in FIG. 5, preferably, an overcoat layer601 is formed on top of the counter substrate body 20R and the shadingfilm 500. Although not shown in FIG. 5, more preferably, a SOG film orthe like is formed on the overcoat layer 601. Consequently, similar tothe first and second embodiments, the entire surfaces of the counterelectrode 21 and the alignment layer 22 can be planarized.

[0108] A structure in which a silicate glass film, such as an NSG film,is formed between the overcoat layer 601 and the SOG film is alsoembraced in the present invention.

[0109] In the structure shown in FIG. 4 in which no gap G is presentbetween the shading film 500 and the recesses 700, an overcoat layer601, a SOG film, etc., may be formed depending on the case. The reasonfor this is that by this way, planarization is also expected and theplanarized surface is more reliably obtained.

[0110] Third Embodiment

[0111] A third embodiment of the present invention will be describedwith reference to FIG. 6. FIG. 6 is an enlarged sectional view similarto FIG. 4, but shows a different structure. An electro-optical deviceshown in FIG. 6 differs from the electro-optical device shown in FIG. 4in that a color filter 800 is provided on top of the shading film 500and an overcoat layer 602 is provided on top of the color filter 800.

[0112] The color filter 800 is composed of R, G, and B colored polymermaterials or the like, and the individual colors correspond to thepixels. The color filter 800 may be formed by a dying method or pigmentdispersion method in which R, G, and B colored layer patterns areobtained by photolithography, or by a printing method orelectrodeposition method in which colored patterns are obtained byprinting or electrodeposition. By the presence of such a color filter800, the individual colors, R, G, and B corresponding to the pixels canbe displayed, and a color image can be displayed in the electro-opticaldevice as a whole.

[0113] Additionally, in the color filter 800 shown in FIG. 6, theadjacent R and G layers, G and B layers, and B and R layers are formedso as to overlap with each other. In such a structure, it is possible toform a color filter which can function in the same manner with a smallerarea compared with a commonly used type in which the individual colorfilters are separated from each other, thus being suitable for theminiaturization of the electro-optical device.

[0114] In the electro-optical device provided with such a color filter800, the shading film 500 is arranged at the positions corresponding tothe boundaries of the individual colors, R, G, and B. This arrangementprevents color mixing, and a clearer image can be obtained.

[0115] Since the color filter 800 in the third embodiment shown in FIG.6 is formed on the planarized surface in which the shading film 500 isembedded in the counter substrate body 20R described in the secondembodiment, the color filter can be formed substantially flatly.

[0116] This embodiment is more advantageous over the case in which anovercoat layer 602 is formed after the color filter 800 is formed in thestate (conventional state) having steps resulting from the formation ofthe shading film on the counter substrate body 20R, or in which theovercoat layer 602 is further planarized. That is, in the thirdembodiment in which an overcoat layer 602 is formed on substantiallyplanarized color filter 800, the surface determined by the overcoatlayer 602 is obviously flatter compared with the related art case. Ofcourse, if the overcoat layer 602 is further planarized by CMP, a SOGfilm formation process, or the like, the electro-optical device can befabricated more efficiently and easily compared with the related artcase.

[0117] In the third embodiment, the color filter 800 and the overcoatlayer 602 are provided based on the second embodiment in which theshading film 500 is formed in the recesses 700. However, in the presentinvention, the similar structure can be formed based on the firstembodiment.

[0118] Fourth Embodiment

[0119] A fourth embodiment of the present invention will be describedwith reference to FIG. 7. FIG. 7 is an enlarged sectional view similarto FIG. 6, but shows a different structure. An electro-optical deviceshown in FIG. 7 differs from the electro-optical device shown in FIG. 6in that a color filter 801 and an overcoat layer 603 are formed asunderlayers to the shading film 500.

[0120] That is, in FIG. 7, the color filter 801 and the overcoat layer603 are formed in that order on the counter substrate body 20R, and thenthe shading film 500 is formed. Recesses 702 are formed in the overcoatlayer 603, and the shading film 500 is formed in the recesses 702. Theovercoat layer 603 is subjected to planarization treatment, which may beperformed before the recesses 702 are formed or, as will be describedbelow with respect to the fabrication method, may be performedsimultaneously with the formation of the shading film 500 in therecesses 702 after the recesses 702 are formed.

[0121] In such a structure, of course, undesirable effects of the stepsresulting from the shading film can be eliminated. “The overcoat layer603” in the fourth embodiment corresponds to an example of “theinterlayer insulating film” of the present invention.

[0122] Although the shading film 500 is formed in the recesses 702 inthe fourth embodiment, the shading film 500 may be formed directly onthe overcoat layer 603 without forming the recesses 702 in the mannersimilar to that in the first embodiment depending on the case.

[0123] Fifth Embodiment

[0124] A fifth embodiment of the present invention will be describedwith reference to FIG. 8. FIG. 8 is an enlarged sectional view similarto FIG. 4, but shows a different structure. The electro-optical deviceshown in FIG. 8 differs from the electro-optical device shown in FIG. 6in that an array of microlenses 900 is provided. As shown in FIG. 8, thearray of microlenses 900 is formed as the underlayer to a cover glass950 and on the surface of the counter substrate body 20R. The coverglass 950 is bonded with the microlenses 900 and the counter substratebody 20R by an adhesive layer 960 containing an appropriate adhesive,etc. The adhesive layer 960 is not always applied to the entire surfaceof the counter substrate body 20R as shown in FIG. 8, and in some cases,the adhesive layer 960 may be applied to the peripheral region only. Theshading film 500 is formed in the recesses 703 formed in the cover glass950, and a counter electrode 21 and an alignment layer 22 are formed ontop thereof.

[0125] As shown in FIG. 8, each of the elements of the array ofmicrolenses 900 (each microlens) is substantially shaped like a dome,and the individual elements correspond to the individual pixels. Themicrolenses 900 may be formed, for example, in a method in which aresist applied over the entire surface of the counter substrate body 20Ris subjected to exposure (photolithography) and heat treatment, etc., soas to form a resist film having substantially dome-shaped parts arrayedin a matrix, and using this as a mask, etching is performed on theentire surface of the counter substrate body 20R, and thus the shape ofthe resist film is transferred to the entire surface of the countersubstrate body 20R. Since the microlens 900 enables light entering fromabove in FIG. 8 to be focused in the beam-condensing region (not shownin FIG. 8) on the pixel electrode 9a, as indicated by dashed lines shownin FIG. 8, utilization of the incident light can be enhanced.

[0126] In such a structure, it is also possible to eliminate theundesirable effects of the steps resulting from the shading film. “Thecover glass 950” in the fifth embodiment corresponds to an example of“the interlayer insulating film” of the present invention. Although themicrolens shown in FIG. 8 is a convex lens with respect to the liquidcrystal layer, the microlens may be a concave lens, or a combination ofa convex lens and a concave lens.

[0127] Specific Examples of Shading Films

[0128] Specific examples of shading films in the individual embodimentswill be described below. The three structures shown in FIGS. 9 to 11 aretaken as the specific examples.

[0129] First, as shown in FIG. 9, a shading film 500 is a single-layeredfilm formed of one material. Examples of the material include metallicchromium (Cr), a resin black in which carbon (C) or titanium (Ti) isdispersed in a photoresist, and metallic materials, such as nickel (Ni).

[0130] Next, as shown in FIG. 10, a shading film 501 having atwo-layered structure composed of two materials may be used. Forexample, a two-layered structure formed of metallic chromium (Cr) andchromium oxide (Cr₂O₃) may be used. In such a case, the shading film 501is for low reflectance use and the shading performance is exhibitedmainly by absorbing incident light.

[0131] Furthermore, as shown in FIG. 11, a shading film 502 having athree-layered structure formed of three materials may be used. Forexample, a three-layered structure formed of aluminum (Al), chromium(Cr), and chromium oxide (Cr₂O₃) deposited in that order from the lightincident side may be used. The shading film 502 has a thickness of, forexample, approximately 400 to 500 nm.

[0132] In the shading film 502, when the Al layer is considered as theincident side, most of the incident light is reflected by the Al layerhaving a extremely high reflective power, and accumulation of uselessheat generated by the absorption of light does not occur in the shadingfilm or in the device, and also, feeble light passing through the Allayer is blocked by the Cr layer and the Cr₂O₃ layer, thus exhibitingvery high shading performance.

[0133] The three-layered structure composed of the combination ofmaterials described above has an advantage in that it is easilyfabricated, in addition to its very high shading performance. The reasonfor this is that, as a combination of a high reflectance material and alow reflectance material, if an Al layer and a Cr₂O₃ layer or the likeare used to form a BM pattern, the formation is relatively difficult inconsideration of the affinity between both materials. Therefore, byfirst forming a Cr layer on an Al base layer, and then forming a Cr₂O₃layer by oxidizing the Cr layer, a shading film having a highreflectance layer and a low reflectance layer can be easily and reliablyformed.

[0134] In any case, the present invention is applicable to the shadingfilm 500 formed of one layer (refer to FIGS. 1 and 2) and alsoapplicable to the multilayered shading films 501 and 502. Since theheight of the multilayered shading film 501 or 502 is generally largerthan that of the single-layered shading film 500, the advantage of thepresent invention that the undesirable effects of the steps resultingfrom the formation of the shading film can be reduced or eliminated ismore effectively exhibited.

[0135] Circuit Configuration and Operation of Electro-optical Device andDetailed Structure of Pixel Region

[0136] With respect to the electro-optical device described above, thecircuit configuration and operation thereof and the structure of thepixel region will be described below with reference to FIGS. 12, 13, and14.

[0137]FIG. 12 is a circuit diagram showing an equivalent circuitincluding various elements, lines, etc., provided on a plurality ofpixels formed in a matrix which constitute the image display region inan electro-optical device.

[0138] In each of the plurality of pixels formed in a matrix whichconstitute the image display region of the electro-optical device inthis embodiment, a pixel electrode 9 a and a TFT 30 to switch the pixelelectrode 9 a are formed. A data line 6 a is electrically connected tothe source of the TFT 30. Image signals S1, S2, . . . , Sn to be writteninto the data lines 6 a may be supplied in that order line by line, orthe image signals may be supplied to a plurality of data lines 6 aadjacent to each other group by group.

[0139] A scanning line 3 a is electrically connected to the gate of theTFT 30, and scanning signals G1, G2, . . . , Gm are supplied in thatorder line by line in a pulsed form. The pixel electrode 9 a iselectrically connected to the drain of the TFT 30. The pixel electrodes9 a write the image signals S1, S2, . . . , Sn supplied from the datalines 6 a at a predetermined timing by turning off the TFTs 30 which areswitching elements for a certain period.

[0140] The image signals S1, S2, . . . , Sn written at a predeterminedlevel into the liquid crystal which is an example of the electro-opticalmaterial through the pixel electrodes 9 a are retained for a certainperiod in the spaces between the liquid crystal and the counterelectrode formed on the counter substrate. Since the alignment of themolecular assembly and the order of the liquid crystal are changed inresponse to the level of voltage applied, light is modulated, thusachieving a gray scale display. In the normally white mode, thetransmittance with respect to incident light is decreased in response tothe voltage applied for each pixel, and in the normally black mode, thetransmittance with respect to incident light is increased in response tothe voltage applied for each pixel, and overall, light having a contrastcorresponding to the image signals is emitted from the electro-opticaldevice.

[0141] In order to reduce or avoid the leakage of the retained imagesignals, storage capacitors 70 are added parallel to the liquid crystalcapacitors formed between the pixel electrodes 9 a and the counterelectrode. Capacitor lines 300, which include capacitor electrodes onthe fixed potential side of the storage capacitors and which are fixedat a constant potential, are provided along the scanning lines 3 a.

[0142] Next, the structure of the pixel region of the electro-opticaldevice in this embodiment will be described with reference to FIGS. 13and 14. FIG. 13 is a plan view showing a plurality of pixels placedadjacent to each other in an electro-optical device provided with datalines, scanning lines, pixel electrodes, etc., and FIG. 14 is asectional view taken along plane A-A′ of FIG. 13. In FIG. 14, in orderto make the individual layers and elements recognizable in the drawing,different scale sizes are used for the individual layers and elements.

[0143] In FIGS. 13 and 14, the electro-optical device is provided withthe TFT array substrate 10 and the counter substrate 20 which have beendescribed above. The TFT array substrate body 10R is formed of, forexample, a quartz substrate, a glass substrate, or a silicon substrate,and the counter substrate body 20R is composed of, for example, a glasssubstrate or a quartz substrate.

[0144] In FIG. 13, a plurality of transparent pixel electrodes 9 a (theoutline thereof is indicated by the dashed lines 9 a′) are formed in amatrix on the TFT array substrate 10 of the electro-optical device. Datalines 6 a and scanning lines 3 a are placed along the boundaries of thepixel electrodes 9 a vertically and horizontally, respectively.

[0145] The scanning line 3 a is placed so as to face channel regions 1a′ which are the hatched sections shown in FIG. 13, and a portion of thescanning line 3 a functions as a gate electrode. At each intersection ofthe scanning lines 3 a and the data lines 6 a, A TFT 30 to switch thepixel is provided in which the scanning line 3 a acting as the gateelectrode is placed so as to face the channel region 1 a′. As shown inFIG. 14, the TFT 30 has a lightly doped drain (LDD) structure. The TFT30 includes the scanning line 3 a, the channel region 1 a′ of asemiconductor layer 1 a which is formed of, for example, a polysiliconfilm and in which a channel is formed by an electric field from thescanning line 3 a, and an insulating film 2 including a gate insulatingfilm which insulates the scanning line 3 a from the semiconductor layer1 a, and the TFT 30 also includes a low-concentration source region 1 b,a low-concentration drain region 1 c, a high-concentration source region1 d, and a high-concentration drain region 1 e of the semiconductorlayer 1 a.

[0146] The data line 6 a which is placed orthogonal to the scanning line3 a is electrically connected to the high-concentration source region 1d through a contact hole 81. Additionally, an intermediary layer formedof the same film as an intermediary layer 71 which will be describedbelow may be formed, and the data line 6 a and the high-concentrationsource region 1 d may be electrically connected to each other throughthe intermediary layer and two contact holes.

[0147] In FIG. 14, the storage capacitor 70 is formed in which theintermediary layer 71 functioning as the capacitor electrode on thepixel potential side, which capacitor electrode connects to thehigh-concentration drain region 1 e and the pixel electrodes 9 a, and aportion of the capacitor line 300 functioning as the capacitor electrode(on the fixed potential side) are placed so as to face each other with adielectric film 75 therebetween.

[0148] The capacitor lines 300 extend along the scanning lines 3 a in astriped pattern when viewed in a plan view, and at the sectionsoverlapping with the TFTs 30, the capacitor lines 300 protrude upwardand downward as shown in FIG. 13. The capacitor line 300 is preferablyformed of a conductive shading film containing a high-melting-pointmetal, and functions as a shading layer to shield the TFTs 30 fromincident light, in addition to the function as the capacitor electrodeon the fixed potential side of the storage capacitor 70. The capacitorline 300 preferably extends from the image display region 10 a in whichthe pixel electrodes 9 a are placed to the periphery thereof, and iselectrically connected to a constant potential source so as to have afixed potential. As the constant potential source, a constant potentialsource of positive or negative power supplied to the data line drivecircuit 101, or a constant potential supplied to the counter electrode21 of the counter substrate 20 may be used.

[0149] On the other hand, the pixel electrode 9 a is one of theelectrodes to apply a predetermined voltage to the liquid crystal layer50. As shown in FIG. 14, the pixel electrode 9 a is electricallyconnected to the high-concentration drain region 1 e of thesemiconductor layer 1 a through the contact holes 85 and 83 with theintermediary layer 71 therebetween. The pixel electrode 9 a is formed ofa transparent conductive film, such as an ITO film.

[0150] An alignment layer 16 which has been subjected to predeterminedalignment treatment, such as rubbing treatment, is provided on the pixelelectrode 9 a. The alignment layer 16 is formed of a transparent organicfilm, such as a polyimide film.

[0151] In the electro-optical device shown in FIGS. 13 and 14, a lowershading film 11 a is also provided below the TFTs 30. The lower shadingfilm 11 a is formed into a grid shape by patterning so as to delimit theaperture regions of the individual pixels. The aperture regions are alsodelimited by the data lines 6 a extending vertically and the capacitorlines 300 extending horizontally which intersect each other in FIG. 13.

[0152] An insulating underlayer 12 is provided under the TFTs 30. Theinsulating underlayer 12 insulates the lower shading film 11 a from theTFTs 30. Since the insulating underlayer 12 is formed on the entiresurface of the TFT array substrate 10, the insulating underlayer 12 alsoavoids the changes in characteristics of the TFTs 30 to switch pixelsdue to roughness during surface polishing of the TFT array substrate 10,contaminants remaining after cleaning, etc.

[0153] A first interlayer insulating film 41 is formed on the scanningline 3 a. The contact hole 81 leading to the high-concentration sourceregion 1 d and the contact hole 83 leading to the high-concentrationdrain region 1 e are formed in the first interlayer insulating film 41.

[0154] The intermediary layer 71 and the capacitor line 300 are formedon the first interlayer insulating film 41, and a second interlayerinsulating film 42 is formed thereon. The contact hole 81 leading to thehigh-concentration source region 1 d and the contact hole 85 leading tothe intermediary layer 71 are formed in the second interlayer insulatingfilm 42.

[0155] The data line 6 a is formed on the second interlayer insulatingfilm 42, and a planarized third interlayer insulating film 43 is formedthereon. The contact hole 85 leading to the intermediary layer 71 isformed in the third interlayer insulating film 43.

[0156] The surface of the third interlayer insulating film 43 isplanarized by CMP or the like, thereby reducing alignment defects of theliquid crystal layer 50 due to the steps resulting from various linesand elements placed therebelow.

[0157] A counter electrode 21 is formed on the entire surface of thecounter substrate 20, and an alignment layer 22 which has been subjectedto predetermined alignment treatment, such as rubbing treatment, isprovided under the counter electrode 21. The counter electrode 21 isformed of a transparent conductive film, such as an ITO film. Thealignment layer 22 is formed of a transparent organic film, such as apolyimide film.

[0158] A shading film 500 shaped in a grid pattern is provided on thecounter substrate 20 as the underlayer to the counter electrode 21 andthe alignment layer 22. As described above, the shading film 500 doesnot necessarily have a grid shape, and may be formed, for example, in astriped pattern along the scanning lines 3 a.

[0159] In this embodiment, as described above, the shading film 500 isembedded in the counter substrate body 20R or the interlayer insulatingfilm, such as the overcoat layer 603 (refer to the fourth embodimentshown in FIG. 7), the cover glass 950 (refer to the fifth embodimentshown in FIG. 8), formed on the counter substrate body 20R. In thestructure shown in FIG. 14, a recess 700 is formed in the countersubstrate body 20R, and the shading film 500 is embedded in the recess700 (corresponding to the second embodiment). Because of such astructure, undesirable effects of steps resulting from the formation ofthe shading film are not produced or can be reduced in this embodiment.

[0160] Fabrication Method

[0161] A method for fabricating the electro-optical device according tothe second embodiment will be described with reference to the flowchartshown in FIG. 15 and to FIGS. 16 and 17.

[0162] First, a counter substrate body 20R is prepared. After thesurface of the counter substrate body 20R is cleaned and dried, a recess700 having a predetermined pattern is formed (step S11). The recess 700may be formed by a photolithographic process or the like.

[0163] That is, as shown in FIG. 16, after a photoresist 711 is appliedto the counter substrate body 20R, followed by pre-baking (FIG. 16(a)),exposure is performed by ultraviolet light or the like through a photomask having the same pattern as that of the recess 700 to be formed(FIG. 16(b)). Herein, “the same pattern as that of the recess 700” is,for example, a grid pattern, as described above. Next, the exposedsections are removed, namely, development is performed, followed bypost-baking to cure the remaining resist 711 (FIG. 16(c)). Lastly,pattern etching is performed using the resist layer as a mask and theresist 711 is removed. The recess 700 having the predetermined patternis thereby formed (FIG. 16(d)). Additionally, although a positive typeresist is used in the method described above, a negative type resist mayalso be used.

[0164] Referring back to FIG. 15, the shading film 500 is formed on thecounter substrate body 20R provided with the recess 700 (step S12). Inorder to form the shading film 500, for example, by sputtering or thelike, a shading film is formed on the entire surface of the countersubstrate body 20R including the sections in which the recess 700 isformed and the sections in which the recess 700 is not formed, and thenthe shading film in the sections in which the recess 700 is not formedis removed by the photolithographic process or the like described withreference to FIG. 16.

[0165] Herein, in this embodiment, as a method for forming (or leaving)the shading film 500 only in the recess 700, a process which is far moreeffective than the photolithographic process will be proposed. Forexample, CMP (Chemical Mechanical Polishing) may be mentioned (see stepS12). Herein, CMP is a technique in which the surfaces of a substrateand a polishing cloth (pad) are brought into contact with each otherwhile both the substrate and the polishing cloth are rotated or thelike, and simultaneously, a polishing liquid (slurry) is supplied to thecontact section, and thus the surface of the substrate is planarized bypolishing taking advantages of the synergistic effect of both mechanicaland chemical actions.

[0166] In such a process, as shown in FIG. 17, first, a shading film500A which is formed over the entire surface of the counter substratebody 20R is polished (FIG. 17(a)), and secondly, a surface 20Ra of thecounter substrate body 20R other than the sections in which the recess700 is formed and the shading film 500A inside the recess 700 arepolished (FIG. 17(b)). Thereby, the structure in which the shading film500 is formed in the recess 700 only or the structure in which theshading film 500 is embedded in the recess 700 is obtained. By such aprocess, it is also possible to obtain an extremely flat surface withrespect to the counter substrate body 20R in which the shading film 500is embedded. (Such planarization treatment may be referred to as “adamascene process by CMP”.)

[0167] In order to completely embed the shading film 500 in the recess700 without any gaps, for example, reflowing may be combined with theprocess described above.

[0168] Instead of CMP, a spin on glass (SOG) film formation process maybe used as the planarization process. Herein, the SOG film formationprocess is a technique in which an appropriate organic liquid or thelike is applied to a substrate while rotating the substrate so that theliquid produces a horizontal surface, and then by solidifying theliquid, a planarized surface is obtained.

[0169] When the shading film 500 is formed in the recess 700 so that agap is present between the shading film 500 and the recess 701 asdescribed with reference to FIG. 5, an overcoat layer 601 may be formedon top of the shading film 500 or a SOG film may be further formed onthe overcoat layer 601.

[0170] It is also possible to combine the various processes describedabove (for example, CMP after the formation of the overcoat layer 601)in order to planarize the surface of the counter substrate body 20R inwhich the shading film 500 is embedded.

[0171] In any case, the examples described above, or other examples,such as the one in which an etch back process or the like is used forplanarization, are basically embraced in the present invention.

[0172] Additionally, when a multilayered shading film is formed as shownin FIG. 10 or 11, the layers are deposited in sequence while thesputtering process is appropriately controlled (for example, sputteringtime is controlled) so that the individual layers have the desiredthicknesses, and then the various types of planarization treatment maybe performed.

[0173] After the shading film 500 which is embedded in the countersubstrate body 20R is formed and the entire surface thereof isplanarized, a counter electrode 21 is formed on top thereof (step S13).The counter electrode 21 may be formed by sputtering or the like usingan ITO target. The thickness thereof is preferably approximately 50 to200 nm.

[0174] In the counter electrode 21 thus formed, cracking or the like dueto the steps does not occur because the entire surface thereof is flat.

[0175] After the counter electrode 21 is formed, an alignment layer 22is formed on top of the counter electrode 21 (step S14). The alignmentlayer 22 may be formed, for example, by a method in which after analignment layer material, such as polyamic acid or a soluble polyimide,is applied by flexographic printing, calcining and firing are performedon the alignment layer material, and finally, rubbing treatment isperformed.

[0176] Herein, in the rubbing treatment, the surface of the firedalignment layer 22 is rubbed in a predetermine direction by a buffingcloth wound around a metallic roller or the like. By such treatment, thepolymer backbone of the polyimide of the alignment layer is drawn in therubbing direction and the liquid crystal molecules can be aligned in thedrawing direction, and thus the molecular orientation of the liquidcrystal can be aligned in a predetermined direction. Additionally, afterthe rubbing treatment is completed, in order to remove tissue slicesfrom the buffing cloth adhering to the surface of the alignment layer 22and chips scraped off the alignment layer 22 itself, the substrate isdipped in ultrapure water and ultrasonic cleaning is performed, and thendrying is performed by exposing the substrate to isopropyl alcohol vaporfor draining.

[0177] In this embodiment, the rubbing treatment can be performeduniformly on the entire surface of the alignment layer 22. The reasonfor this is that since the alignment layer 22 is formed on top of thecounter electrode 21 which is formed on the planarized counter substratebody 20R and shading film 500, the entire surface of the alignment layer22 is also flat.

[0178] The fabrication of the counter substrate 20 is thereby completed.

[0179] The TFT array substrate 10 and the electro-optical device arefabricated according to the flowchart shown in FIG. 18.

[0180] First, as the TFT array substrate body 10R, for example, a quartzsubstrate, a glass substrate, or a silicon substrate is prepared, andappropriate cleaning and drying treatment is performed (step S21). Next,on the substrate body 10R, various elements, such as the TFTs 30 and thestorage capacitors 70, the lines, the interlayer insulating films 41,42, and 43, etc., which are shown in FIG. 14, etc., are formed (stepS22). The pixel electrodes 9 a and the alignment layer 16 are formed(step S23), and the fabrication of the TFT array substrate 10 is therebycompleted.

[0181] After the TFT array substrate 10 and counter substrate 20provided with various layers are prepared, the TFT array substrate 10and the counter substrate 20 are bonded with each other by the sealant52 shown in FIGS. 1 and 2 so that the upper and lower alignment layers22 and 16 face each other (step S24). At this stage, in order tomaintain a predetermined distance between the two substrates 10 and 20,spacers (not shown in the drawing) are dispersed. Next, a liquid crystalwhich is, for example, a mixture of several types of nematic liquidcrystals, is injected into the space between the TFT array substrate 10and the counter substrate 20 (step S25). The liquid crystal injectionmay be performed by a vacuum method or the like.

[0182] The electro-optical device is thereby completed.

[0183] Embodiment of Electronic Apparatus

[0184] Next, with respect to a projection color display device which isan embodiment of an electronic apparatus in which the liquid crystaldevice described above is used as a light valve, the overall structureand, in particular, the optical structure will be described. FIG. 19 isa schematic sectional view of the projection color display device.

[0185] In FIG. 19, in a liquid crystal projector 1100 which is anexample of the projection color display device in this embodiment, threeliquid crystal modules, each including a liquid crystal device in whichdrive circuits are mounted on a TFT array substrate, are used as lightvalves 100R, 100G, and 100B. In the liquid crystal projector 1100,projection light, which is emitted from a lamp unit 1102 comprising awhite light source, such as a metal halide lamp, is separated by threemirrors 1106 and two dichroic mirrors 1108 into three primary colorlight components R, G, and B. The light components R, G, and B areguided to the light valves 100R, 100G, and 100B corresponding to theindividual primary colors, respectively. At this stage, in particular, Blight is guided through a relay lens system 1121 formed of an incidentside lens 1122, a relay lens 1123, and an emitting side lens 1124 inorder to avoid light loss due to its long optical path. The lightcomponents corresponding to the primary colors which are modulated bythe light valves 100R, 100G, and 100B, respectively, are combined againby a dichroic prism 1112, and then are projected as a color image to ascreen 1120 through a projection lens 1114.

[0186] Other examples of the electronic apparatuses of the presentinvention include liquid crystal televisions, mobile phones, electronicpocket diaries, word processors, viewfinder type or monitor-direct-viewtype video tape recorders, workstations, television telephones, POSterminals, and touch panels, for example.

[0187] Additionally, although the active matrix electro-optical deviceshave been described in the individual embodiments, the present inventionis not limited thereto. That is, the present invention is applicable toa so-called “simple matrix” electro-optical device having a structure inwhich electrode strips are formed on two substrates as electrodes toapply a voltage to an electro-optical material, and the two substratesare placed to face each other so that the electrode strips on theindividual substrates intersect each other. The present invention isalso applicable to an active matrix electro-optical device which usesTFDs instead of the TFTs 30. Moreover, the present invention is alsoapplicable to an electro-optical device in which one of the substratesis not provided with an alignment layer, such as an EL device or anelectrophoretic device, and to an electro-optical device in which one ofthe substrates is not provided with an electrode.

[0188] The present invention is not limited to the embodiments describedabove. It is to be understood that the present invention is intended toembrace all such alternatives, modifications, and variations as may fallwithin the spirit and scope of the appended claims and thespecification. Electro-optical devices and electronic apparatuses inwhich such modifications are made are also embraced in the technicalfield of the present invention.

What is claimed is:
 1. An electro-optical device, comprising: a pair ofsubstrates including a first substrate and a second substrate; anelectro-optical material disposed between the pair of substrates; ashading film having a predetermined pattern, the shading film being atleast partially embedded in the first substrate at a surface facing theelectro-optical material; display electrodes disposed above the secondsubstrate at the surface facing the electro-optical material; andswitching elements provided corresponding to the display electrodes. 2.The electro-optical device according to claim 1, further comprising aplanarizing layer which is flush with a surface of the shading filmprovided above the first substrate, or which is an upper layer to theshading film.
 3. The electro-optical device according to claim 1,further comprising an alignment layer which is an uppermost layer to theshading film provided above the first substrate.
 4. An electro-opticaldevice, comprising: a pair of substrates including a first substrate anda second substrate; an electro-optical material disposed between thepair of substrates; a shading film having a predetermined pattern, theshading film being formed on the first substrate at a surface facing theelectro-optical material; display electrodes disposed above the secondsubstrate at the surface facing the electro-optical material; switchingelements provided at positions corresponding to the display electrodes;and a planarizing layer which is flush with a surface of the shadingfilm provided above the first substrate or which is an upper layer tothe shading film.
 5. The electro-optical device according to claim 4,the planarizing layer being formed by chemical mechanical polishing(CMP).
 6. The electro-optical device according to claim 4, theplanarizing layer being a spin-on-glass (SOG) film.
 7. Theelectro-optical device according to claim 4, further comprising a colorfilter and an overcoat layer formed on top of the color filter, thecolor filter and the overcoat layer being provided above the firstsubstrate above or below the shading film, a surface of the overcoatlayer being planarized.
 8. The electro-optical device according to claim4, the shading film being placed in a recess formed in the firstsubstrate.
 9. The electro-optical device according to claim 4, theshading film being placed in a recess formed in an interlayer insulatingfilm provided above the first substrate.
 10. The electro-optical deviceaccording to claim 4, further comprising an overcoat layer which is anupper layer to the shading film.
 11. The electro-optical deviceaccording to claim 4, further comprising an alignment layer as anoutermost layer above the first substrate.
 12. The electro-opticaldevice according to claim 1, further comprising a display electrodeplaced above the first substrate at the surface facing theelectro-optical material.
 13. The electro-optical device according toclaim 12, the display electrode placed above the first substrate being atransparent counter electrode formed in the entire image display region.14. The electro-optical device according to claim 1, further comprisingmicrolenses provided above the first substrate.
 15. The electro-opticaldevice according to claim 1, the shading film including a plurality oflayers.
 16. The electro-optical device according to claim 15, theplurality of layers including at least one of an aluminum layer, achromium layer, and a chromium oxide layer.
 17. A method for fabricatingan electro-optical device, comprising: forming a shading film having apredetermined pattern so as to be partially embedded in a firstsubstrate at a surface to be facing an electro-optical material; formingdisplay electrodes above a second substrate at a surface to be facingthe electro-optical material; forming switching elements correspondingto the display electrodes; bonding the first substrate and the secondsubstrate with each other around peripheries thereof; and injecting theelectro-optical material into a space between the bonded first andsecond substrates.
 18. A method for fabricating an electro-opticaldevice, comprising: forming a shading film having a predeterminedpattern above a first substrate at a surface to be facing anelectro-optical material; performing planarization treatment on the sameplane as the surface of the shading film provided above the firstsubstrate or on the level above the shading film; forming displayelectrodes above a second substrate at a surface to be facing theelectro-optical material; forming switching elements corresponding tothe display electrodes; bonding the first substrate and the secondsubstrate with each other around peripheries thereof; and injecting theelectro-optical material into a space between the bonded first andsecond substrates.
 19. An electronic apparatus, comprising: theelectro-optical device according to claim 1.